Photography Microscope Recommendation

I would like to get a microscope to look at the microscopic life in my aquariums. I'd also like to be able to photograph it. I'm looking for something decent but not professional level. Does anybody know what I should look for or have specific recommendations? I'm planning to get a used one from EBay. Hopefully I can find a science student who's graduated and doesn't need theirs anymore. Budget...I want something decent. If I can afford it I'll get it. If not, well it's an interesting idea. I'll just stick with my camera macro lens.

Thanks.

-Brian